Intimal and neointimal fibroplasia leading to late failures of at least 50% of arterial reconstructions bear a striking resemblance to atherosclerosis obliterans and appears to be hemodynamically dependent. Based upon clinical observations in failed arterial reconstructions experimental models have been developed in dogs by alteration of local hemodynamic conditions, which develop florid lesions within three months and recognizable lesions within 1 hour, recognizable by light and electronmicroscopy. Objectives are: to document the evolution of the lesions in high and low flow states by progressively earlier study by electron microscopy to attempt to determine whether atherosclerosis, intimal and neointimal fibroplasia are identical. To test the hypothesis that vibratory phenomena detected by high fidelity recording of sounds produced by altered flow play a role in this process, by delivering critical frequencies to the blood vessel wall. To test the clinical observations that metabolic alterations may influence the reaction, by noting the effects of these on the experimental models already standardized.